1. Field of the Invention
The invention proceeds from a switch having a vacuum interrupter which is arranged between two supply terminals and can be actuated by a drive, and containing a tubularly constructed, evacuated housing with a fixed and a movable contact member, in which the fixed contact member is supported by means of a fixed contact carrier on a first one of the two supply terminals, and a contact carrier, which can be moved by a drive, of the movable contact member is guided out of the housing in a vacuum-tight fashion by means of a bellows and held on the tube axis by means of a slideway and is connected in an electrically conductive fashion to a second one of the two supply terminals.
If such a switch is used as the master switch of an electric traction vehicle, then this switch must execute a comparatively large number of switching operations and is consequently subjected to significant wear. Particularly susceptible to wear in this case is the vacuum interrupter, which is provided in the switch housing and whose vacuum tightness is determined first and foremost by the bellows, which guide the movable contact member outwards out of the tube interior in a vacuum-tight fashion.
2. Discussion of Background
The invention refers to a prior art as in specified, for example, U.S. Pat. No. 4,071,727 A, EP 0 054 670 A2 or EP 0 132 804 B1. A vacuum interrupter described in this prior art has a slideway for a movable contact member which is guided into the tube interior in a vacuum-tight fashion by means of a bellows. In this case, the slideway ensures the guidance of the movable contact member is directed substantially along the tube axis. However, when this vacuum interrupter is fitted into a switch housing, it is not possible reliably to exclude damage to the vacuum interrupter.